21102133123 has 2 divisors, whose sum is σ = 21102133124. Its totient is φ = 21102133122.

The previous prime is 21102133067. The next prime is 21102133187. The reversal of 21102133123 is 32133120112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102133123 is a prime.

It is a super-3 number, since 3×21102133123³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21102133123.

It is not a weakly prime, because it can be changed into another prime (21102136123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551066561 + 10551066562.

It is an arithmetic number, because the mean of its divisors is an integer number (10551066562).

Almost surely, 2^21102133123 is an apocalyptic number.

21102133123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102133123 is an equidigital number, since it uses as much as digits as its factorization.

21102133123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21102133123 its reverse (32133120112), we get a palindrome (53235253235).

It can be divided in two parts, 21102133 and 123, that added together give a triangular number (21102256 = T₆₄₉₆).

The spelling of 21102133123 in words is "twenty-one billion, one hundred two million, one hundred thirty-three thousand, one hundred twenty-three".